Finding the Fourth Proportional to 21,217.31, 31,777.52 and 10,131.81

Step by Step Solution

1. Step 1: Write the proportion equation
   21,217.31 : 31,777.52 = 10,131.81 : x
2. Step 2: Convert to fraction form
   21,217.31/31,777.52 = 10,131.81/x
3. Step 3: Cross multiply
   21,217.31x = 31,777.52 × 10,131.81
4. Step 4: Simplify right side
   21,217.31x = 321,963,794.91
5. Step 5: Solve for x
   x = 321,963,794.91/21,217.31
6. Step 6: Final answer
   x = 15,174.58